Lifting mechanism for desk

ABSTRACT

A lifting mechanism for desk including a first bracket, a second bracket, and at least one lever assembly is provided. The first bracket includes a first plane. The second bracket includes a second plane. The lever assembly is connected between the first bracket and the second bracket so that the first bracket moves close to or moves away from the second bracket through the lever assembly, and the first plane is tilted relative to the second plane when the first bracket is away from the second bracket. The lever assembly includes at least two levers, and lengths of the at least two levers are different.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefits of U.S. provisional application Ser. No. 62/540,571, filed on Aug. 3, 2017, and Taiwan application serial no. 107208539, filed on Jun. 26, 2018. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND Technical Field

The invention relates to a lifting mechanism. More particularly, the invention relates to a lifting mechanism for desk.

Description of Related Art

In the information age, the time for people to sit at the desk to work, read and so on has increased significantly. Hence, desk users begin to pay increasing attention to how desks can be used more conveniently. In order to satisfy needs from the users, desks that can be lifted and lowered have hit the market, that is, the heights of desktops of such lifting desks can be adjusted by users themselves according to their own needs. Nevertheless, the existing lifting desks are unable to effectively provide convenient and comfortable using experience to the users to meet users' needs.

SUMMARY

The invention provides a lifting mechanism for desk which provides a desk body that can be lifted and lowered through a lever assembly and an angle of the desk body relative to a user that can be adjusted, so that the user can work and read on a desktop with different heights and angles and thus enjoys a convenient and comfortable using experience.

A lifting mechanism for desk provided by an embodiment of the invention includes a first bracket, a second bracket, and at least one lever assembly. The first bracket includes a first plane. The second bracket includes a second plane. The lever assembly is connected between the first bracket and the second bracket so that the first bracket moves close to or moves away from the second bracket through the lever assembly, and the first plane is tilted relative to the second plane when the first bracket is away from the second bracket. The lever assembly includes at least two levers, and lengths of the at least two levers are different.

In an embodiment of the invention, a tilt angle between the first plane and the second plane increases as a distance between the first bracket and the second bracket increases when the first bracket moves away from the second bracket.

In an embodiment of the invention, the first plane is parallel to or is tilted relative to the second plane when the first bracket moves close to and overlaps the second bracket.

In an embodiment of the invention, the lifting mechanism for desk further includes at least one torsion spring, disposed at a position where the lever assembly is pivoted to the first bracket or the second bracket. The torsion spring is abutted between the lever assembly and the first bracket or the second bracket so as to drive the lever assembly to rotate with respect to the first bracket or drive the lever assembly to rotate with respect to the second bracket.

In an embodiment of the invention, the lever assembly includes a first lever and a second lever. One end of the first lever is pivoted to one of the first bracket and the second bracket, and the other end of the first lever is movably disposed at the other one of the first bracket and the second bracket through a first rail assembly. One end of the second lever is pivoted to one of the first bracket and the second bracket, and the other end of the second lever is movably disposed at the other one of the first bracket and the second bracket through a second rail assembly.

In an embodiment of the invention, the first rail assembly includes a first rail and a first sliding member. The first sliding member is slidably coupled to the first rail, the first rail is disposed at the first bracket or the second bracket, and one end of the first lever is pivoted to the first sliding member. The second rail assembly includes a second rail and a second sliding member. The second sliding member is slidably coupled to the second rail, the second rail is disposed at the second bracket or the first bracket, and one end of the second lever is pivoted to the second sliding member.

In an embodiment of the invention, the first sliding member or the second sliding member has an engaging flange, and the lifting mechanism for desk further includes a positioning member and a stirring member. The positioning member includes a pivoting end, a forcing end, and a plurality of positioning slots located between the pivoting end and the forcing end, the pivoting end is pivoted to the first bracket or the second bracket such that the positioning slots are located next to a sliding path of the first sliding member or a sliding path of the second sliding member. The stirring member is pivoted to the first bracket or the second bracket, and the stirring member includes a protruding rod movably extending to the forcing end. The stirring member is adaptable to be driven by an external force so that the protruding rod pushes the forcing end, such that the positioning member rotates with respect to the first bracket or the second bracket and enables the engaging flange to be engaged in one of the positioning slots.

In an embodiment of the invention, the lifting mechanism for desk further includes an elastic member abutted between the first bracket and the positioning member or abutted between the second bracket and the positioning member. The elastic member constantly drives the positioning member and the engaging flange to be engaged with each other, or the elastic member constantly drives the positioning member and the engaging flange to be away from each other.

In an embodiment of the invention, the lifting mechanism for desk further includes a pivoting member pivoted between the first lever and the second lever, the first lever crosses the second lever.

In an embodiment of the invention, a length of the first lever is less than a length of the second lever. The lifting mechanism for desk further includes a user side and a back side. When the first bracket moves away from the second bracket, the first bracket moves towards the user side away from the back side, and a position where the first lever is pivoted to the first bracket and a position where the second lever is pivoted to the second bracket are both located at the user side.

In an embodiment of the invention, the first lever is parallel to the second lever, and the first lever and the second lever are pivoted to the second bracket and are slidably disposed at the first bracket. The lever assembly further includes a third lever, one end of the third lever is pivoted to the first bracket, and the other end of the third lever is pivoted to the first lever.

In an embodiment of the invention, a length of the third lever is less than a length of the first lever, and the length of the first lever is less than a length of the second lever.

In an embodiment of the invention, the lifting mechanism for desk further includes a user side and a back side. When the first bracket moves away from the second bracket, the first bracket moves towards the user side away from the back side. A position where the first lever is pivoted to the second bracket and a position where the third lever is pivoted to the first bracket are both located at the user side.

In an embodiment of the invention, the lever assembly includes a first lever and a second lever. Two opposite ends of the first lever are respectively pivoted to the first bracket and the second bracket. Two opposite ends of the second lever are respectively pivoted to the second bracket and the first bracket.

In an embodiment of the invention, a length of the first lever is less than a length of the second lever, and the first lever is parallel to the second lever. The lifting mechanism for desk further includes a user side and a back side. When the first bracket moves away from the second bracket, the first bracket moves towards the user side away from the back side, and the first bracket and the second bracket are not aligned with each other. A position where the first lever is pivoted to the second bracket is located at the user side, and a position where the second lever is pivoted to the first bracket is located at the back side.

To sum up, in the lifting mechanism for desk provided by the invention, the first bracket is connected to the second bracket through the at least one lever assembly. The lengths of the at least two levers of the lever assembly are different. The angle of the desk body is changed when the first bracket moves close to or moves away from the second bracket through the lever assembly. Therefore, the user may adjust the height of the desk body according to his/her own needs. When changing the height of the desk body, the user may adjust the angle of the desk body at the same time to switch between the sitting posture and the standing posture so as to work and read on the desk body more conveniently. Since the user may work and read when changing his/her postures at the same time, the user is able to enjoy a more convenient and comfortable using experience when using the lifting mechanism for desk.

To make the aforementioned more comprehensible, several embodiments accompanied with drawings are described in detail as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

FIG. 1 is a schematic view of a lifting mechanism for desk according to an embodiment of the invention.

FIG. 2 is a schematic view of the lifting mechanism for desk of FIG. 1 in another state.

FIG. 3 and FIG. 4 are explosive views of the lifting mechanism for desk of FIG. 1.

FIG. 5 to FIG. 7 are schematic views illustrating state changes of the lifting mechanism for desk.

FIG. 8 is a portion of the lifting mechanism for desk of FIG. 1.

FIG. 9 is a schematic view of a lifting mechanism for desk according to another embodiment of the invention.

FIG. 10 to FIG. 12 are schematic views illustrating an actuation principle of the lifting mechanism for desk of FIG. 9.

FIG. 13 is a schematic view of a lifting mechanism for desk according to still another embodiment of the invention.

FIG. 14 to FIG. 16 are schematic views illustrating an actuation principle of the lifting mechanism for desk of FIG. 13.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a schematic view of a lifting mechanism for desk according to an embodiment of the invention. FIG. 2 is a schematic view of the lifting mechanism for desk of FIG. 1 in another state. With reference to FIG. 1 and FIG. 2 together, in this embodiment, a lifting mechanism for desk 100 includes a first bracket 110, a second bracket 120, and lever assemblies 130A and 130B, but one of the lever assemblies can be omitted. The first bracket 110 includes a first plane P1. The second bracket 120 includes a second plane P2. The lever assemblies 130A and 130B are connected between the first bracket 110 and the second bracket 120 so that the first bracket 110 moves close to or moves away from the second bracket 120 through the lever assemblies 130A and 130B, and the first plane P1 is tilted relative to the second plane P2 when the first bracket 110 is away from the second bracket 120. Herein, each of the lever assemblies 130A and 130B includes at least two levers, and lengths of the at least two levers are different. A desk body 200 is adaptable to be assembled on the first bracket 110. A folded/unfolded movement is generated between the first bracket 110 and the second bracket 120 through the movement of the lever assemblies 130A and 130B. Further, when the desk body 200 moves away from the second bracket 120, the first plane P1 is tilted relative to the second plane P2 of the second bracket 120, such that the first bracket 110 and the desk body 200 thereon can move with respect to the second bracket 120 via the movement of the lever assemblies 130A and 130B, so that the desk body 200 is enabled to ascend/descend, and an angle is changed. That is, when the second bracket 120 is supported on a platform (not shown, e.g., another desktop or a working platform), the mechanism makes the desk body 200 to ascend/descend with respect to the platform and an angle of the desk body 200 with respect to a user to be changed, such that the user can work and read on the desktop more conveniently and comfortably.

Note that each of the lever assemblies provided by the invention substantially includes at least four connecting ends to be movably connected to the first bracket and the second bracket. At least two of the connecting ends are pivoted to the first bracket, the second bracket, or the first bracket and the second bracket, and at least two of the connecting ends are rotatably or slidably connected to the first bracket, the second bracket, or the first bracket and the second bracket. Different embodiments are incorporated herein for description.

It should be mentioned that the embodiment is described by using the pair of lever assemblies 130A and 130B that are on the left and right sides of the drawing and respectively disposed on the first bracket 110 and the second bracket 120 as an example. The following descriptions are also provided based on the example. Nevertheless, in another embodiment that is not shown, the relative movement generated between the first bracket 110 and the second bracket 120 can be achieved by employing only one of the lever assemblies 130A or 130B located at one side. Therefore, no repetition is provided in the following embodiments.

In this embodiment, the first bracket 110 includes parts 112, 114A and 114B. The part 112 is horizontally connected between the parts 114A and 114B, forming an “H”-shaped structure, such that the desk body 200 is assembled thereto and leans against the “H”-shaped structure. An upper surface of the desk body 200 is the defined first plane P1. Likewise, the second bracket 120 includes parts 122A, 122B, 124A, and 124B that are adaptable to lean against or be placed on the platform (not shown). Lower surfaces of the parts 124A and 124B are the defined second plane P2. Here, the first bracket 110 and the second bracket 120 are mostly the same in terms of structure, but their shape is not limited to the “H”-shaped structure; for example, they may be formed in a “U” shape.

The lever assembly 130A includes a first lever 134A, a second lever 134B, and a pivoting member 136A, wherein the pivoting member 136A is pivoted between the first lever 134A and the second lever 134B, and the first lever 134A crosses the second lever 134B such that the lever assembly 130A can rotate. Likewise, the lever assembly 130B on the other side includes a first lever 134C, a second lever 134D, and a pivoting member 136B, wherein the pivoting member 136B is pivoted between the first lever 134C and the second lever 134D such that the first lever 134C crosses the second lever 134D, and the lever assembly 130B can rotate as well. In this way, an angle between the first lever 134A and the second lever 134B is changed.

FIG. 3 and FIG. 4 are explosive views of different parts of the lifting mechanism for desk of FIG. 1. Since there are many members, the schematic views are illustrated separately so that FIG. 3 can clearly show the form of the members in the upper half part of the lifting mechanism for desk, and FIG. 4 can clearly show the form of the members in the lower half part of the lifting mechanism for desk. With reference to FIG. 3 and FIG. 4, the lifting mechanism for desk 100 of this embodiment further includes a first rail assembly 150A and a second rail assembly 150B (a first rail assembly 150C and a second rail assembly 150D are disposed on the other side). It should be indicated that the structures of the first rail assemblies 150A and 150C and the second rail assemblies 150B and 150D are constructed in the same manner. Therefore, the same reference numerals are used to denote related rail members in the following descriptions; meanwhile, the first rail assembly 150A and the second rail assembly 150B are employed in the following descriptions to refer to related rail assemblies. Here, the first rail assembly 150A includes a first rail 154A, a first slider 152A, and a carrier 156A (the same also applies to members 152C, 154C, and 156C; no repetition is provided herein), wherein the first slider 152A and carrier 156A may be regarded as a first sliding member in the first rail assembly 150A (i.e. in another embodiment that is not shown, they can be an integrally formed structure). The first rail 154A is slidably disposed in the part 114A of the first bracket 110. A fourth connecting end E4 of the second lever 134B is pivoted to the carrier 156A of the first sliding member and is further assembled with the first slider 152A so as to slide back and forth in the part 114A. The second rail assembly 150B also has the same structure. The difference between the first and the second rail assembly is that the second rail 154B is slidably disposed in the part 124A of the second bracket 120, and a second connecting end E2 of the first lever 134A is pivoted to the carrier 156B of the sliding member and is further assembled with a second slider 152B of the sliding member so as to slide back and forth in the part 124A (the same also applies to members 152D, 154D, and 156D; no repetition is provided herein).

In addition, the lifting mechanism for desk 100 further includes torsion springs 160A, 160B, 160C, and 160D respectively disposed in the first bracket 110 and the second bracket 120 and configured to be abutted between the lever assemblies 130A and 130B and the first bracket 110 or the second bracket 120. The torsion springs 160A to 160D are configured to serve as a source of power for the lever assemblies 130A and 130B to rotate. For example, the torsion spring 160A is disposed within the part 124A of the second bracket 120, is located at a third connecting end E3 of the second lever 134B, and is abutted between the part 124A and second lever 134B. The torsion spring 160B is disposed within the part 124B on the other side of the second bracket 120 to be abutted between the part 124B and the second lever 134D. The rest of torsion springs 160C and 160D also serve to drive the lever assemblies 130A and 130B to perform the movement. Nevertheless, the embodiment provides no limitation to the direction of driving the lever assemblies 130A and 130B.

FIG. 5 to FIG. 7 are schematic views illustrating state changes of the lifting mechanism for desk, wherein the lever assembly 130A is illustrated with a viewing angle of a right-side view of FIG. 1. Meanwhile, the lever assembly 130B on the other side also actuates in the same manner; therefore, no repetition is provided herein. The part 114A of the first bracket 110 is illustrated in a perspective view (i.e. outlined with dotted-lines) so as to clearly show the relation of the members at the position. In the embodiment, a beam 132 is horizontally connected between the first lever 134A and the first lever 134C, such that the two lever assemblies 130A and 130B can actuate simultaneously. With reference to FIG. 5 to FIG. 7 first for the descriptions of the actuating mode of the lever assembly 130A.

The first lever 134A includes a first connecting end E1 and a second connecting end E2 opposite to each other. The first connecting end E1 is pivoted to the part 114A of the first bracket 110, and the second connecting end E2 is slidably coupled to the first bracket 110 through the first rail assembly 150A (shown in FIG. 3). Nevertheless, in other embodiments that are not shown, the first connecting end may also be pivoted to the second bracket, and the second connecting end may be slidably coupled to the first bracket. The second lever 134B includes a third connecting end E3 and a fourth connecting end E4 opposite to each other. The third connecting end E3 is pivoted to the part 124A of the second bracket 120, and the fourth connecting end E4 is slidably coupled to the part 114A of the first bracket 110. Nevertheless, in other embodiments that are not shown, the third connecting end may also be pivoted to the first bracket, and the fourth connecting end may be slidably coupled to the second bracket.

In this embodiment, a length L1 of the first lever 134A is less than a length L2 of the second lever 134B. Through such configuration, when the lever assembly 130A (the same also applies to 130B, no repetition is provided herein) performs the actuating action, the first lever 134A and the second lever 134B rotate relatively about the pivoting member 136A as the center. Being restricted to the corresponding relation between the levers and brackets, the second connecting end E2 and fourth connecting end E4 respectively slide along the first bracket 110 and the second bracket 120 due to the rotation action. Meanwhile, the first connecting end E1 and third connecting end E3 rotate with respect to the first bracket 110 and the second bracket 120 (without generating relative movement). The pivoting member 136A moves in a direction parallel to the second connecting end E2 and the fourth connecting end E4, causing the first bracket 110 to move away from the second bracket 120. Moreover, when the first bracket 110 moves away from the second bracket 120, as a distance between the first bracket 110 and the second bracket 120 increases, tilt angles θ1, θ2, or θ3 (illustrated in FIG. 5 to FIG. 7, that is, an included angle between the first plane P1 and the second plane P2) between the first bracket 110 and the second bracket 120 increases as well.

With reference to FIG. 7, when the first bracket 110 moves close to and overlaps the second bracket 120, the first bracket 110 may be parallel to or may be tilted relative to the second bracket 120. To be specific, the pivoting member 136A may be pivoted at a middle position of the first lever 134A and a middle position of the second lever 134B, that is, the pivoting member 136A keeps a distance, (L1)/2, from the first connecting end E1 (or the second connecting end E2), and the pivoting member 136A also keeps a distance, (L2)/2, from the third connecting end E3 (or the fourth connecting end E4). In this way, since each of the first lever 134A and the second lever 134B is divided into two equal parts by the pivoting member 136A, when the first bracket 110 moves close to and overlaps the second bracket 120, the first bracket 110 and the second bracket 120 are parallel to each other. In other words, by changing a position where the pivoting member 136A is pivoted on the first lever 134A or the second lever 134B, the pivoting member 136A is made to deviate from the middle position of the first lever 134A or the middle position of the second lever 134B. As such, when the first bracket 110 moves close to and overlaps the second bracket 120, the first bracket 110 is tilted relative to the second bracket 120. Accordingly, in the lifting mechanism for desk 100 provided by the invention, by changing the position where the pivoting member 136A is pivoted on the first lever 134A or the second lever 134B, the angle of the desk body 200 relative to the user is changed, so as to satisfy needs from different user groups and allow users to enjoy a more convenient and comfortable using experience.

With reference to FIG. 6 and FIG. 7, the lifting mechanism for desk includes a user side U1 and a back side U2. The user side U1 is one side of the lifting mechanism for desk 100 close to the user when the user actually uses the lifting mechanism for desk. A position where the first lever 134A is pivoted to the first bracket 110 and a position where the second lever 134B is pivoted to the second bracket 120 are both located at the user side U1. In a process during which the first bracket 110 moves away from the second bracket 120 (or a process during which the first bracket 110 ascends upwards), when the lifting mechanism for desk 100 is unfolded from a state shown in FIG. 7 to a state shown in FIG. 6, since the length L2 of the second lever 134B is less than the length L1 of the first lever 134A, an extent to which the first bracket 110 is lifted up by the first lever 134A is less than an extent to which the first bracket 110 is lifted up by the second lever 134B when the first bracket 110 moves away from the second bracket 120. With reference to FIG. 5, when the first bracket 110 ascends upwards, the tilt angle between the first bracket 110 and the second bracket 120 gradually increases from the tilt angle θ3 (shown in FIG. 7) to the tilt angle θ2 (shown in FIG. 6) and then further increases to the tilt angle θ1 (shown in FIG. 5). Further, the first bracket 110 moves towards the user side U1 away from the back side U2. In other words, θ1>θ2>θ3.

In other words, when the user uses the lifting mechanism for desk 100, the angle of the desk body 200 may gradually change as the first bracket 110 is lifted up. Further, regardless of the heights of lifting, the desk body 200 can face the user. In this way, the user may use the lifting mechanism for desk 100 more conveniently and comfortably. In other embodiments that are not shown, the length of the first lever may be greater than the length of the second lever, and the desk body may move towards the back side.

FIG. 8 is a portion of the lifting mechanism for desk of FIG. 1, which is illustrated with a viewing angle of a right-side view of FIG. 1. Referring to FIG. 3, FIG. 4, and FIG. 8 together, it should be pointed out that the lifting mechanism for desk 100 further includes a positioning assembly consisting of a positioning member 144, a stirring member 142, and an elastic member 146. As shown in FIG. 3 and FIG. 4, the lifting mechanism for desk 100 includes two sets of positioning assemblies respectively disposed at the opposite sides of the first bracket 110. The following embodiment is described with only one set of the positioning assembly. In the embodiment, the positioning member 144 includes a pivoting end 144 c, a forcing end 144 b, and a plurality of positioning slots 144 a located between the pivoting end 144 c and the forcing end 144 b. The pivoting end 144 c is pivoted to the part 114A of the first bracket 110, and the positioning member 144 is disposed along the part 114A. As such, the positioning slots 144 a are all located next to a sliding path of the first slider 152A and the carrier 156A of the first sliding member. The stirring member 142 is pivoted to the part 114A of the first bracket 110.

As shown in FIG. 3, the part 114A further includes a pivoting plate structure 114A1 extending laterally. The stirring member 142 is substantially pivoted in the pivoting plate structure 114A1 of the part 114A, and the stirring member 142 includes a protruding rod 142 a that movably extends to the forcing end 144 b. As the drawing shows, the forcing end 144 b is formed with a recessed profile such that the protruding rod 142 a can insert in and accordingly stir the positioning member 144. More specifically, the stirring member 142 is adaptable to be driven by an external force such that the protruding rod 142 a can push the forcing end 144 b, so that the positioning member 144 rotates with respect to the part 144A of the first bracket 110 via the pivoting end 144 c.

With reference to FIG. 5 to FIG. 7, correspondingly, the carrier 156A of the first sliding member further includes an engaging flange 156 e, which, for example, is a bending structure of an edge of the carrier 156A. Also, the lifting mechanism for desk 100 further includes an abutting part 148 assembled in the part 114A to accommodate the elastic member 146. The forcing end 144 b of the positioning member 144 is also accommodated in the abutting part 148. In other words, the elastic member 146 is disposed to be abutted between the abutting part 148 and the forcing end 144 b of the positioning member 144. With such configuration, the elastic member 146 can drive the positioning member 144 to rotate via an elastic force; that is, the forcing end 144 b is driven by the protruding rod 142 a and elastic member 146 to change its position.

For instance, in the state shown in FIG. 5, the user applies a force to the stirring member 142 such that the positioning member 144 rotates in the manner as shown by the arc-shaped arrow in FIG. 5, so that the engaging flange 156 e is separated from the positioning slot 144 a. At this time, the user can apply another force (via the first bracket 110) to the lever assemblies 130A and 130B, for example, by applying a downward force so that the first bracket 110 moves close to the second bracket 120. As FIG. 6 shows, the elastic member 146 is also compressed by the force. Next, when the first bracket 110 moves to the position shown in FIG. 7, the user removes the force applied to the stirring member 142. Hence, the elastic force of the elastic member 146 drives the positioning member 144 to rotate to be restored towards a direction of the desk body 200, such that the engaging flange 156 e is engaged in one of the positioning slots 144 a. Accordingly, the elastic member 146 in the embodiment constantly drives the positioning member 144 to be engaged with the engaging flange 156 e. The invention provides no limitation to the configuration and distance of the positioning slots 144 a; the positioning slots 144 a are provided where necessary depending on the need.

In another embodiment that is not shown, the elastic member can constantly drive the positioning member and the engaging flange to be away from each other via the stretching and deforming characteristics.

FIG. 9 is a schematic view of a lifting mechanism for desk according to another embodiment of the invention. With reference to FIG. 9, a lifting mechanism for desk 300 includes a first bracket 310, a second bracket 320, and lever assemblies 330A and 330B. The first bracket 310 includes a first plane P1. The second bracket 320 includes a second plane P2. The lever assemblies 330A and 330B are connected between the first bracket 310 and the second bracket 320 so that the first bracket 310 moves close to or moves away from the second bracket 320 through the lever assemblies 330A and 330B, and the first plane P1 is tilted relative to the second plane P2 when the first bracket 310 is away from the second bracket 320. A desk body 200 is adaptable to be assembled on the first bracket 310. A folded/unfolded movement is generated between the first bracket 310 and the second bracket 320 through the movement of the lever assemblies 330A and 330B. Further, when the desk body 200 moves away from the second bracket 320, the first plane P1 is tilted relative to the second plane P2, such that the first bracket 310 and the desk body 200 thereon can move with respect to the second bracket 320 via the movement of the lever assemblies 330A and 330B, so that the desk body 200 is enabled to ascend/descend, and an angle is changed.

The first bracket 310 includes parts 312, 314A, and 314B. The part 312 is horizontally connected between the parts 314A and 314B, forming an “H”-shaped structure, such that the desk body 200 is assembled thereto and leans against the “H”-shaped structure. An upper surface of the desk body 200 is the defined first plane P1. Likewise, the second bracket 320 includes parts 322A, 322B, 324B and 324B that are adaptable to lean against or be placed on the platform (not shown). Lower surfaces of the parts 324A and 324B are the defined second plane P2. Here, the first bracket 310 and the second bracket 320 are mostly the same in terms of structure, but their shape is not limited to the “H”-shaped structure; for example, they may be formed in a “U” shape.

In this embodiment, the first levers 334A and 334C are parallel to the second levers 334B and 334D. Moreover, the first levers 334A and 334C and the second levers 334B and 334D are pivoted to the second bracket 320 and are slidably disposed at the first bracket 310. The lever assemblies 330A and 330B further includes third levers 338A and 338B. One end of each of the third levers 338A and 338B is pivoted to the first bracket 310, and the other end of each of the third levers 338A and 338B is pivoted to the first lever 334A.

In addition, the lifting mechanism for desk 300 further includes torsion springs 360A and 360B disposed in the first bracket 310 or the second bracket 320 and configured to be abutted between the lever assemblies 330A and 330B and the first bracket 310 or the second bracket 320. The torsion spring 360A is configured to serve as a source of power for the lever assemblies 330A and 330B to rotate. For example, the torsion spring 360A is disposed within the part 324A of the second bracket 320, is located at one end of the first lever 334A, and is abutted between the part 324A and first lever 334A. The torsion spring 360B is disposed within the part 324B on the other side of the second bracket 320 to be abutted between the part 324B and the first lever 334C. Nevertheless, the embodiment provides no limitation to the direction of driving the lever assemblies 330A and 330B.

FIG. 10 to FIG. 12 are schematic views illustrating an actuation principle of the lifting mechanism for desk of FIG. 9 and illustrating an actuation principle of the first bracket 310 and the second bracket 320 of the lifting mechanism for desk 300 of FIG. 9 at different angles. With reference to FIG. 9 and FIG. 12, in this embodiment, a length L3 of each of the third levers 338A and 338B is less than a length L1 of each of the first levers 334A and 334C, and the length L1 of each of the first lever 334A and 334C is less than a length of each of the second lever 334B and 334D. The lifting mechanism for desk 300 further includes a user side U1 and a back side U2. The user side U1 is one side of the lifting mechanism for desk 300 close to the user when the user actually uses the lifting mechanism for desk. When the first bracket 310 moves away from the second bracket 320, the first bracket 310 moves towards the user side U1 away from the back side U2. Positions where the first levers 334A and 334C are pivoted to the second bracket 320 and positions where the third levers 338A and 338B are pivoted to the first bracket 310 are all located at the user side U1. In a process during which the first bracket 310 moves away from the second bracket 320 (or a process during which the first bracket 310 ascends upwards), when the lifting mechanism for desk 300 is unfolded from a state shown in FIG. 12 to a state shown in FIG. 11, since the length L2 of each of the second levers 334B and 334D is less than the length L1 of each of the first levers 334A and 334C, an extent to which the first bracket 310 is lifted up by the first levers 334A and 334C is less than an extent to which the first bracket 310 is lifted up by the second levers 334B and 334D when the first bracket 310 moves away from the second bracket 320. With reference to FIG. 10 and FIG. 11, when the first bracket 310 ascends upwards, a tilt angle between the first bracket 310 and the second bracket 320 gradually increases from a tilt angle θ6 (shown in FIG. 12) to a tilt angle θ5 (shown in FIG. 11) and then further increases to a tilt angle θ4 (shown in FIG. 10). Further, the first bracket 310 moves towards the user side U1 away from the back side U2. In other words, θ4>θ5>θ6, wherein each of the tilt angles θ4, θ5, and θ6 is the included angle between the first plane P1 and the second plane P2.

The third levers 338A and 338B may be pivoted to middle positions of the first levers 334A and 334C through pivoting members 336A and 336B, that is, the pivoting member 336A keeps a distance, (L1)/2, from an end of the first lever 334A, and the pivoting member 336B keeps a distance, (L1)/2, from an end of the first lever 334C. In this way, since each of the first lever 334A, the first lever 334C, the second lever 334B, and the second lever 334D is divided into two equal parts by the third lever 338A, as shown in FIG. 12, when the first bracket 310 moves close to and overlaps the second bracket 320, the first bracket 310 and the second bracket 320 are parallel to each other. In other words, by changing positions where the third levers 338A and 338B are pivoted to the first levers 334A and 334C, the third levers 338A and 338B are made to deviate from the middle positions of the first levers 334A and 334C. As such, when the first bracket 310 moves close to and overlaps the second bracket 320, the first bracket 310 is tilted relative to the second bracket 320. Accordingly, in the lifting mechanism for desk 300 provided by the invention, by changing the positions where the third levers 338A and 338B are pivoted to the first levers 334A and 334C, the angle of the desk body 200 relative to the user is changed, so as to satisfy needs from different user groups and allow users to enjoy a more convenient and comfortable using experience.

FIG. 13 is a schematic view of a lifting mechanism for desk according to still another embodiment of the invention. With reference to FIG. 13, a lifting mechanism for desk 400 includes a first bracket 410, a second bracket 420, and at least one lever assemblies 430A and 430B. The first bracket 410 includes a first plane P1. The second bracket 420 includes a second plane P2. The lever assemblies 430A and 430B are connected between the first bracket 410 and the second bracket 420 so that the first bracket 410 moves close to or moves away from the second bracket 420 through the lever assemblies 430A and 430B, and the first plane P1 is tilted relative to the second plane P2 when the first bracket 410 is away from the second bracket 420. A desk body 200 is adaptable to be assembled on the first bracket 410. A folded/unfolded movement is generated between the first bracket 410 and the second bracket 420 through the movement of the lever assemblies 430A and 430B. Further, when the desk body 200 moves away from the second bracket 420, the first plane P1 is tilted relative to the second plane P2, such that the first bracket 410 and the desk body 200 thereon can move with respect to the second bracket 420 via the movement of the lever assemblies 430A and 430B, so that the desk body 200 is enabled to ascend/descend, and an angle is changed.

The first bracket 410 includes parts 414A and 414B. The second bracket 420 includes parts 422A, 422B, 424A, and 424B that are adaptable to lean against or be placed on the platform (not shown).

In this embodiment, the lever assemblies 430A and 430B includes first levers 4034A and 434C and second levers 434B and 434D. The first levers 434A and 434C are parallel to the second levers 434B and 434D. Two opposite ends of each of the first levers 434A and 434C are respectively pivoted to the first bracket 410 and the second bracket 420, and two opposite ends of each of the second levers 443B and 443D are respectively pivoted to the second bracket 420 and the first bracket 410.

In addition, the lifting mechanism for desk 400 further includes torsion springs 460A and 460B disposed in the first bracket 410 or the second bracket 420 and configured to be abutted between the lever assemblies 430A and 430B and the first bracket 410 or the second bracket 420. The torsion spring 460A is configured to serve as a source of power for the lever assemblies 430A and 430B to rotate. For example, the torsion spring 460A is disposed within the part 424A of the second bracket 420, is located at one end of the first lever 434A, and is abutted between the part 424A and first lever 434A. The torsion spring 460B is disposed within the part 424B on the other side of the second bracket 420 to be abutted between the part 424B and the first lever 434C. Nevertheless, the embodiment provides no limitation to the direction of driving the lever assemblies 430A and 430B.

FIG. 14 to FIG. 16 are schematic views illustrating an actuation principle of the lifting mechanism for desk of FIG. 13 and illustrating an actuation principle of the first bracket 410 and the second bracket 420 of the lifting mechanism for desk 400 of FIG. 13 at different angles. With reference to FIG. 13 and FIG. 16, in this embodiment, a length L1 of each of the first levers 434A and 434C is less than a length of each of the second levers 434B and 434D. The lifting mechanism for desk 400 further includes a user side U1 and a back side U2. The user side U1 is one side of the lifting mechanism for desk 400 close to the user when the user actually uses the lifting mechanism for desk. When the first bracket 410 moves away from the second bracket 420, the first bracket 410 moves towards the user side U1 away from the back side U2. Moreover, the first bracket 410 and the second bracket 420 are not aligned with each other. Positions where the first levers 434A and 434C are pivoted to the second bracket 420 are located at the user side U1, and positions where the second levers 434B and 434D are pivoted to the first bracket 410 are located at the back side U2. In a process during which the first bracket 410 moves away from the second bracket 420 (or a process during which the first bracket 410 ascends upwards), when the lifting mechanism for desk 400 is unfolded from a state shown in FIG. 16 to a state shown in FIG. 15, since the length L2 of each of the second levers 434B and 434D is less than the length L1 of each of the first levers 434A and 434C, an extent to which the first bracket 410 is lifted up by the first levers 434A and 434C is less than an extent to which the first bracket 410 is lifted up by the second levers 434B and 434D when the first bracket 410 moves away from the second bracket 420. With reference to FIG. 14 and FIG. 15, when the first bracket 410 ascends upwards, a tilt angle between the first bracket 410 and the second bracket 420 gradually increases from a tilt angle θ9 (shown in FIG. 16) to a tilt angle θ8 (shown in FIG. 15) and further increases to a tilt angle θ7 (shown in FIG. 14). Further, the first bracket 410 moves towards the user side U1 away from the back side U2. In other words, θ7>θ8>θ9, wherein each of the tilt angles θ7, θ8, and θ9 is the included angle between the first plane P1 and the second plane P2.

In view of the foregoing, in the lifting mechanism for desk provided by the embodiments of the invention, the length of the first lever is provided to be less than the length of the second lever, and thereby, the extent to which the first bracket is lifted up by the first lever is less than the extent to which the first bracket is lifted up by the second lever. As such, the tilt angle of the desk body relative to the second bracket gradually increases when the desk body is lifted up at the same time. In this way, the user can work or read on the lifting mechanism for desk provided by the invention more conveniently and comfortably.

It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure covers modifications and variations provided that they fall within the scope of the following claims and their equivalents. 

What is claimed is:
 1. A lifting mechanism for desk, comprising: a first bracket, comprising a first plane; a second bracket, comprising a second plane; and at least one lever assembly, connected between the first bracket and the second bracket so that the first bracket moves close to or moves away from the second bracket through the at least one lever assembly, wherein the first plane is tilted relative to the second plane when the first bracket moves away from the second bracket, and the at least one lever assembly comprises at least two levers, and lengths of the at least two levers are different.
 2. The lifting mechanism for desk as claimed in claim 1, wherein a tilt angle between the first plane and the second plane increases as a distance between the first bracket and the second bracket increases when the first bracket moves away from the second bracket.
 3. The lifting mechanism for desk as claimed in claim 1, wherein the first plane is parallel to or is tilted relative to the second plane when the first bracket moves close to and overlaps the second bracket.
 4. The lifting mechanism for desk as claimed in claim 1, further comprising: a torsion spring, disposed at a position where the at least one lever assembly is pivoted to the first bracket or the second bracket, wherein the torsion spring is abutted between the at least one lever assembly and the first bracket or the second bracket so as to drive the at least one lever assembly to rotate with respect to the first bracket or drive the at least one lever assembly to rotate with respect to the second bracket.
 5. The lifting mechanism for desk as claimed in claim 1, wherein the at least one lever assembly comprises: a first lever, one end of the first lever being pivoted to one of the first bracket and the second bracket, the other end of the first lever being movably disposed at the other one of the first bracket and the second bracket through a first rail assembly; and a second lever, one end of the second lever being pivoted to one of the first bracket and the second bracket, the other end of the second lever being moveably disposed at the other one of the first bracket and the second bracket through a second rail assembly.
 6. The lifting mechanism for desk as claimed in claim 5, wherein the first rail assembly comprises a first rail and a first sliding member, the first sliding member is slidably coupled to the first rail, the first rail is disposed at the first bracket or the second bracket, and one end of the first lever is pivoted to the first sliding member, wherein the second rail assembly comprises a second rail and a second sliding member, the second sliding member is slidably coupled to the second rail, the second rail is disposed at the second bracket or the first bracket, and one end of the second lever is pivoted to the second sliding member.
 7. The lifting mechanism for desk as claimed in claim 6, wherein the first sliding member or the second sliding member has an engaging flange, and the lifting mechanism for desk further comprising: a positioning member, comprising a pivoting end, a forcing end, and a plurality of positioning slots located between the pivoting end and the forcing end, the pivoting end being pivoted to the first bracket or the second bracket such that the positioning slots are located next to a sliding path of the first sliding member or a sliding path of the second sliding member; and a stirring member, pivoted to the first bracket or the second bracket, the stirring member comprising a protruding rod movably extending to the forcing end, the stirring member being adaptable to be driven by an external force so that the protruding rod pushes the forcing end, such that the positioning member rotates with respect to the first bracket or the second bracket and enables the engaging flange to be engaged in one of the positioning slots.
 8. The lifting mechanism for desk as claimed in claim 7, further comprising: an elastic member, abutted between the first bracket and the positioning member or abutted between the second bracket and the positioning member, the elastic member constantly driving the positioning member and the engaging flange to be engaged with each other, or the elastic member constantly driving the positioning member and the engaging flange to be away from each other.
 9. The lifting mechanism for desk as claimed in claim 5, further comprising: a pivoting member, pivoted between the first lever and the second lever, the first lever crossing the second lever.
 10. The lifting mechanism for desk as claimed in claim 5, further comprising a user side and a back side, wherein a length of the first lever is less than a length of the second lever, the first bracket moves towards the user side away from the back side when the first bracket moves away from the second bracket, and a position where the first lever is pivoted to the first bracket and a position where the second lever is pivoted to the second bracket are both located at the user side.
 11. The lifting mechanism for desk as claimed in claim 5, wherein the first lever is parallel to the second lever, the first lever and the second lever are pivoted to the second bracket and are slidably disposed at the first bracket, and the at least one lever assembly further comprises: a third lever, one end of the third lever being pivoted to the first bracket, the other end of the third lever being pivoted to the first lever.
 12. The lifting mechanism for desk as claimed in claim 11, wherein a length of the third lever is less than a length of the first lever, and the length of the first lever is less than a length of the second lever.
 13. The lifting mechanism for desk as claimed in claim 12, further comprising a user side and a back side, wherein the first bracket moves towards the user side away from the back side when the first bracket moves away from the second bracket, and a position where the first lever is pivoted to the second bracket and a position where the third lever is pivoted to the first bracket are both located at the user side.
 14. The lifting mechanism for desk as claimed in claim 1, wherein the at least one lever assembly comprises: a first lever, two opposite ends of the first lever being respectively pivoted to the first bracket and the second bracket; and a second lever, two opposite ends of the second lever being respectively pivoted to the second bracket and the first bracket.
 15. The lifting mechanism for desk as claimed in claim 14, wherein a length of the first lever is less than a length of the second lever, the first lever is parallel to the second lever, the lifting mechanism for desk further comprises a user side and a back side, the first bracket moves towards the user side away from the back side when the first bracket moves away from the second bracket, and the first bracket and the second bracket are not aligned with each other, wherein a position where the first lever is pivoted to the second bracket is located at the user side, and a position where the second lever is pivoted to the first bracket is located at the back side. 